Control mechanism for elevators



NOV. 12, 1940. DUNN I 2,221,395

CONTROL MECHANISM FOR ELEVATORS Filed June 17, 1958 8 Sheets-Sheet l HOISTING MOTOR /5ELECTOR CONTROL PANEL DRIVING DRUM WIRE DRIVE HALL BUTTON COUNTERWEIGHT HALL BUTTONS ELEVATOR CAR E4213"? surrong HALL BUI'TON FIQI ATTORNEY Nov. 12, 1940. E. 1.. DUNN 2,221,395

CONTROL MECHANISM FOR ELEVATORS Filed June 17, 1938 8 SheetsSheet 2 H7 a W A). :8 INVENTOQ ATTOR N EY NOV. 12, E L D CONTROL MECHANISM FOR ELEVATORS Filed June 17, 1938 l 8 Sheets-Sheet 3 W Lu. 11W INVENTOR BY ATTORNEY Nov. 12, 1940. E. L. DUNN CONTROL MECHANISM FOR ELEVATORS 8 Sheets-Sheet 4 Filed June 17, 1938 Y E N R 0 T W L 13W IN N Nov. 12, 1940. E. L. DUNN 2,221,395

CONTROL MECHANISM FOR ELEVATORS Filed June 17, 1938 8 Sheets-Sheet 5 W L. 11W INVENTOR BY WW /7 '7" ATTORNEY Nov. 12, 1940. E. L. DUNN CONTROL MECHANISM FOR ELEVATORS Filed June 1'7, 1938 8 Sheets-Sheet,- 6

54M! L4. 11W INVENTOR H N R O W A Nov. 12, 1940. E. L. DUNN 2,221,395 v CONTROL MECHANISM FOR ELEVATORS Filed June 1'7, 1938 8 Sheets-Sheet 7 N 2 5 n u: s E N N I L h I.

i Q '2 9 g g i:

Q E 53 g j Nouumsw/ Q v1 :6 Q N o a g:

E13 2 a 1 llll p r" a n g:\ N $5 8 s N Nov. 12, 1940.

E. 1.. DUNN CONTROL MECHANISM FOR ELEVATORS Filed June 17, 1938 8 Sheets-Sheet 8 m "J S; :2

I'll

Ficalb FIGJB Patented Nov. 12, 1940 UNITED STATES PATENT OFFICE CONTROL MECHANISM FOR ELEVATORS Application June 1'7, 1988, Serial No. 214,271

12 Claims.

The invention relates to control mechanism for elevators and especially to control mechanism actuated in accordance with movement of the elevator car.

There are many forms of elevator systems. In many of these, mechanism actuated in accordance with movement of the elevator car is utilized to control the operation of the car. Such mechanism is also used in elevator systems for other purposes, such as in signalling, scheduling and door operation. There are certain advantages in grouping these various operating parts together in a single mechanism driven from the elevator car. The invention is directed to mechanism of this character. Such mechanism is known by various terms in the art, dependent principally upon the purpose served. For convenience, the mechanism will be hereinafter referred to as a selector.

One object of the invention is the provision of a selector in which operating parts may be readily added, subtracted or varied so as to give combinations of apparatus suitable for the requirements of different installations.

Another object of the invention is the provision on a selector of mechanism for controlling the retardation and stopping of the car which is accurate in operation, of simple construction and which is readily accessible for purposes of connecting and adjusting.

Another object of the invention is the provision for the elements of the selector actuated in accordance with car movement of driving mechanism which is reliable in operation, of simple construction and economical to manuiacture.

Features and advantages of the invention will be apparent from the following description and appended claims.

In the drawings: Figure 1 is a simplified schematic representation of an elevator installation embodying a sel' :tor in accordance with the invention;

Figure 2 is a schematic representation of the selector;

Figure 3 is a view in horizontal section taken above the selector crosshead;.

Figure 4 is a detail in side elevation of a portion of the selector mechanism illustrating particularly the pawls and. stopping lugs;

Figure 5 is an enlarged detail of the pawls and stopping lugs;

Figure 6 is a detail of the mechanism for retracting the stopping lugs;

Figure '7 is a detail taken along the line 'l-'! of Figure 6;

Figure 8 is a detail taken along the line 8--8 of Figure 6;

Figure 9 is a detail in side elevation illustrating the mechanism for controlling the retardation and stopping of the elevator car;

Figure 10 is a detail taken along the line ill-40 of Figure 9;

Figure 11 is a detail taken along the line lll l of Figure 10;

Figure 12 is a detail in side elevation illustrating the crosshead panel assembly with various contacting elements arranged thereon;

Figure 13 is a detail in plan view of the crosshead panel assembly and the contacting elements on a floor bar for cooperating with the contacting elements on the crosshead;

Figure 14 is a side view. of switching mechanism mounted on a crosshead panel and its operating cam on a floor bar, this view being taken along the line I l-l4 of Figure 12;

Figure 15 is a front view of the same;

Figure 16 is a side view of a sectional cam on the crosshead panel and switching mechanism on. a floor bar for cooperating therewith, this view being taken along the line l6--l6 of Figure 2;

Figure 17 is a view taken along the line l1--l'| of Figure 16;

- Figure 18 is a view taken along the line l8l8 of Figure 16; and w Figure 19 is a fragmental detail of a contact mounted on a crosshead panel and the contact spring on a floor bar for cooperating therewith.

For a general understanding of a typical elevator installation to which the invention is applicable, reference may be had to Figure 1. An elevator installation has been schematically illustrated in which the car may be controlled for example as disclosed in the patent to Lewis, Waters and Krauer, No. 2,101,146, granted December '7, 1937. Various parts of the system are indicated by legend. The elevator car is raised and lowered by means of a hoisting motor. This motor drives a traction sheave over which pass the hoisting ropes for the car and counterweight. The hoisting motor is controlled by various electromagnetic switches mounted on a control panel. An electromechanical brake is provided and is applied to effect the final stopping operation and hold the car when at rest.

A five-floor installation has been indicated. Up and down push buttons are arranged at the intermediate floors and a single push button is arranged at each terminal floor. These buttons are known as hall buttons. The elevator car is provided with an independent set of push buttons, one button being provided for each floor. These push buttons are known as car buttons.

The hall and car buttons act through floor relays which, in conjunction with the selector and other control apparatus, cause the car to proceed to and stop at the floors for which buttons have been pressed.

The selector is driven from the elevator car.

I The selector drive shaft is provided with a driving drum. This drum is driven by means of piano wire. This wire is arranged in two sections. One section of the wire is attached at one.

end to the top of the elevator car. From the car it extends upwardly to the drum on one side thereof and is wound around the drum in a certain direction in the helical groove provided on the drum. The other end of this section of the wire is secured at the point on the end of the drum where the groove ends. The other section of wire is secured at one end to the top of the counterweight through the intermediary of a spring. From the counterweight it extends upwardly to the drum on the other side and is wound around the drum in the opposite direction in the helical groove to occupy the remaining space. The other end of this section of the wire is secured to the drum at the point where the groove ends. Thus one section of the wire winds up as the other section unwinds in the 1 driving operation, the section which winds up taking up the space vacated by the unwinding section. A silent drive is thus provided which is unaflected by sliding or stretching ropes and the moving parts of the selector are driven in exact synchronism with the elevator car.

Reference may now be had to Figure 2, which illustrates schematically a selector of preferred construction. This figure is for the purpose of giving a comprehensive understanding of the machine and its operation. It is not intended to show the details of construction, such details being illustrated in Figures 3 to 19 inclusive. In the drawings showing details of construction, certain parts, not involved in the operation of the portion of mechanism illustrated in a particular figure of drawings, are not shown in that figure in order that the construction and operation of such portion of the mechanism may be readily.

understood.

Referring also to Figure 3, the selector comprises a frame formed by a base plate 2! and top plate 22 joined together by four corner posts I3 in the form of angle irons. The angle irons are secured to the plates through feet 24, the angle irons being fastened to the feet which in turn are secured to the plates. The selector drive shaft 25 is supported in bearings '28 secured to the base plate. The driving drum 21 for the selector is secured to the outer end of the shaft. This shaft operates through bevel gears 28 and 28 to drive an operating shaft in in bearings ll.

The operating shaft has a sprocket 32 secured to the end thereof for driving an endless sprocket chain 38. This chain extends upwardly over and around an idler sprocket 34 mounted on a tensioning device 35 secured to top plate 22. The tensioning device comprises. a lever 30 which carries a stub shaft upon which idler sprocket 34 is mounted. This lever is pivotally supported by bracket 31 secured to the top plate and at its outer end is arranged between two adjusting nuts spouses 3| arranged on a screw 40 secured to the top plate.

Sprocket chain It acts through a sprocket wheel 4| to drive the selector crosshead 42. The sprocket 4| is mounted on the stub shaft 43 secured to the crosshead in position for the sprocket wheel to mesh with the left hand run of the chain as viewed in Figure 2. A shoe 44 is carried by the crosshead opposite the sprocket wheel in position to maintain the chain in mesh with the sprocket wheel at all times. This shoe is formed on a block I! which is secured to the crosshead by screws 48. The sprocket wheel meshes on its other side with a stationary chain 41 secured at its ends by tensioning bolts 48 to the top and bottom plates. A similar shoe 50 is carried by the crosshead to maintain the stationary chain in mesh with the sprocket wheel at all times. With this arrangement, a 2:1 ratio drive chain movement to crosshead movement is obtained. In other words, for every two inches of chain movement, an inch of crosshead movement is obtained.

The crosshead in its up and down movement slides on a tubular member ,Bl. This tubular member is secured in apertures 52 formed in the top and bottom plates, the arrangement for the upper plate being illustrated in Figure 9. The crosshead is provided with a cylindrical aperture through which the tube extends, the crosshead being slid onto the tube before the top plate is put in place in the assembly operation.

Another tubular member 63 is similarly secured to the top and bottom plates and serves as a further guide for the crosshead. One end of the crosshead is bifurcated to provide guide arms 54 spanning member SI. A guide shoe 5! is supported by each guide arm in position to engage member If and thus maintain the proper angular position of the crosshead on tubular member ii.

The cross head carries a pair of oppositely disposed pawls i6 and 51 for cooperating with stopping lugs 58 mounted on an elongated tubular sleeve 60. The arrangement of these pawls is shown in Figures 4 and 5. Each pawl is pivotally mounted on a pin 6| secured to a bracket 02 carried by an elongated lug 59 of the crosshead. The pawl is biased by spring 63 into position for cooperation with the stopping lugs, this spring being arranged between the end of the pawl and an arm 64 formed on' the bracket. A lug 85 formed on the pawl cooperates with the arm 64 to limit the outward movement of the pawl. The brackets are secured to the crosshead by bolts 61, the heads of the bolts being welded to the bracket. These bolts extend into apertures 6' in elongated lug il, a plurality of the apertures being provided in vertical alignment. This arrangement permits adjusting the positions of the pawls, which is desirable in certain installations to take care of short floor height conditions.

The stopping lugs 58 are carried by collars II adjustably mounted on sleeve 60. A stopping lug is provided for each floor, the collars being in spaced relation on sleeve 80 in accordance with the distance between the floors for which the lugs are provided. The collars are split to permit adjustment and clamping thereof to the sleeve, the collars being clampedin adjusted position by bolts H. Each stopping lug is provided with a threaded stem 12 which extends through an aperture 13 in supporting arm 14 formed on the collar. A shoulder 15 is formed on .this arm against which the lug fits to prevent rotative movement thereof. The lug is clamped in its proper position by means of a nut 16 on the threaded end of the stem. The upper pawl cooperates with the stopping lugs during upward movement of the crosshead and the lower pawl cooperates with the stopping lugs during downward movement of the crosshead.

The stopping lugs are retracted, during the movement of the crosshead, to a position where the pawls clear the lugs. The lugs are maintained retracted until the car arrives at a certain distance from a landing at which a stop is to be made. When this condition is reached, the lugs are released and move into position for cooperation with the pawls. This operation is controlled by an electromagnet 11 mounted on the bottom of top plate 22. This magnet operates a lever 18 which has a rod secured thereto and extending downwardly therefrom into a slot 8| formed in an arm 82 secured to sleeve 00. Energization of the electromagnet causes clockwise movement of lever 18 as viewed in Figure 2, causing, through the action of rod 80 and arm 82, the clockwise movement of sleeve 80. This moves all the stopping lugs to retracted position, where the pawls clear during travel of the crosshead. Upon deenergization of the electromagnet, a spring 83 acts to swing the lever 18 counterclockwise. This in turn, through rod 80 and arm 82, causes counterclockwise movement of sleeve 60 to move the stopping lugs into position for cooperation with the pawls.

Details of the mechanism for retracting the stopping lugs are shown in Figures 6, '1 and 8. The electromagnet 11 comprises a frame formed of two end plates 85 and 86 and a side plate 81 joined as by welding to a top plate 88 and bottom plate 90, the top plate 88 being secured to the top plate 22 of the floor controller frame as by screws. The magnet coil 9| is arranged between the end plates 85 and 80 and is maintained in proper position by a stationary core 92. This core extends through an aperture in end plate 85 and is secured at its end to a plate 93, in turn secured to end plate 85 as by screws 94.

The stationary core is recessed to receive the conical end of the movable core of the magnet. Core 95 extends through'an aperture in end plate 86 and is connected by link 91 to lever 18. This lever is secured to a pivot shaft 98, supported by bearings I00 and IOI in the top and bottom plates of the magnet frame. This lever is made up of two parts, one part, I02, being arranged on the pivot shaft and the other, I03, being secured thereto and connected to link 91. The spring 83 is arranged between one arm of member I02 and end plate 86. This spring acts to bias the lever for counterclockwise rotative movement as viewed in Figure '7. The other arm of member I02' is provided with an adjustable screw I04 for cooperating with thin metal plates I05 secured to side plate 81 to limit the counterclockwise rota tive movement of the lever, thereby bringing the stopping lugs to a stop in proper position for cooperation with the pawls.

The rod- 80 is secured to lever member I03, being provided at its upper end with a threaded stem which extends through a lug I08 on member I03 and being secured to the lug by a nut on the threaded end of the stem. The rod is of square cross-section and the slot 8| in the arm 82, into which the rod extends, is formed with parallel sides to be engaged by the rod. The arm 82 is secured to the sleeve 60 as by welding.

With this arrangement, upon energi'zation of the electromagnet its movable core is pulled inwardly to the position illustrated in Figure 7,

causing clockwise rotative movement of the lever 18 and thus, through rod 80 and arm 82, clockwhere the lugs extend into the path of movementof the pawls. If the crosshead is moving upwardly, the up pawl engages the stopping lug next above as continued upward movement of the crosshead takes place, whereas, if the crosshead is moving downwardly, the down pawl en-' gages the stopping lug next below as continued downward movement of the crosshead takes place. When a lug is engaged by a pawl, the continued movement of the crosshead causes corresponding movement of sleeve 60, that is, continued up-' ward movement of the crosshead causes upward movement of the sleeve, while continued downward movement of the crosshead causes downward movement of the sleeve. The sleeve is arranged on a guide rod I I0 which, for convenience, is secured at its upper end to pivot shaft 98. As this results in rotative movement of the rod, it is mounted at its lower end in a bearing provided in base plate 2|. With such arrangement, the bearing I00 .for the upper end of pivot shaft 98 is arranged as a thrust bearing to take care of any upward thrust which may result from upward movement of sleeve 60 on guide rod IIO.

Movement of sleeve 60 by the pawls is utilized to operate a plurality of switches arranged on the top of the selectorl A sprocket chain III is secured to a lug M2 formed on arm 82. This chain extends upwardly therefrom around a sprocket wheel II3 arranged on a shaft III supported in bearing stands II5 on top plate 22. From this sprocket wheel the chain extends downwardly into tubular member 5|, where it is secured to the top of a counterweight rod H6. The lower end of the counterweight rod has secured thereto an additional chain II1 which extends downward therefrom around an idler pulley II8 pivotally supported in a bracket 9 secured to the base plate 2|. From this pulley the chain extends upwardly to a bracket I20 to which the upper end of the chain is secured. This bracket is adjustably secured to the sleeve 60 to enable any slack in chains I II and II! to be taken up.

A collar I2I is secured to the lower end of counterweight rod II6 for supporting counterweight I22 arranged within tubular member 5|. This counterweight is provided with an aperture I23 through which the counterweight rod |I6 extends and is supported on collar I 2| through the intermediary of a resilient washer I24. The weight of the counterweight is such as to overbalance the weight of sleeve 60, the counterweight being supported by tubular member 5| on a shoulder I25 which may be formed by providing an auxiliary tube inside tubular member 5| at the bottom. Near the top of counterweight rod 6 is secured another collar I26 for supporting balance weights I21. The weight of each balance weight is equal to the weight of a stopping collar and lug on sleeve 60, there being one balance weight provided for each stopping lug.

With this arrangement, upon downward movement of sleeve 60 by downward movement of the crosshead, counterweight I22 and balance weights This retracts the I21 are lifted by the counterweight rod so that. upon rotative movement of the sleeve by electromagnet 11 to withdraw the stopping lug from cooperative engagement with the down pawl, counterweight I22 returns the sleeve to neutral position, being brought to a stop by the engagement of the resilient washer I24 with shoulder I25. Upon upward movement of sleeve by the crosshead, downward movement of counterweight I22 is prevented by shoulder I25, the counterweight rod IIO sliding downwardly through aperture I22 in the counterweight. Thus only the rod and balance weights I21 are moved by the chains during upward movement of sleeve 00 so that, upon retraction of the stopping lug from engagement with the up pawl, the sleeve 50 is returned by gravity to neutral position and brought to a stop by the engagement of collar I2I with resilient washer I24.

Sprocket chain III, in being driven by the above described movement of sleeve 52, causes rotative movement of sprocket wheel H2. The sprocket wheel, in turn, acts through shaft II4 to eii'ect corresponding rotative movement of a plurality of cams to operate switches I22, I2I, I22, I22, I24 and I25. Details of this portion of the mechanism are shown in Figures 9. and 11. The bearing stands III for shaft II4 are secured to the top plate 22 as by screws. An angle member I extends between these stands, being secured as by bolts to brackets I2'I formed on the stands. Switches I22, m, m, m, m and I25 are secured as by screws to this angle member in spaced relation, space being provided for adding switches, if desired. These switches are principally for controlling retardation and stopping of the car. Each of these switches is of the same construction so that only one of them will be described. Details of construction are shown in Figures 10 and 11 and also in Figures 14 and 15 where the switch is shown for use in cgnnection with another portion of the mecha- Each switch comprises a frame I of molded insulating material secured to angle member I25. The frame has a dividing member I extending upwardly from the base portion. A pair of leaf springs I42 is secured as by terminal screws to bosses formed on the frame, one on each side of dividing member I. Each spring has a silver contact tip at its upper end. Protecting stops I44 are formed on each side of member I between which the contact springs extend. The movable contact omprises a lever I45 pivotally mounted on a pin supported in a boss formed on the contact frame and having its upper end I42 bent toward the contact springs. A contact bridging member in the form of an angle I41 having a silver contact insert is secured to the bent end as by a screw I42. The contact lever is biased by spring I into position where the member I41 bridges the contact tips of the contact springs. The contact lever is channel shaped and lugs I5I are formed on the sides of the channel between the ends of the lever to form a support for the pivot pin for operating roller I52. This roller is positioned in the path of movement of cams I52 and I54 to move the lever about its pivot against the force of spring I52 into position to disengage the stationary contact springs.

The operating cams for switches I20, I2I, I22 and I22 are arranged in pairs, the cams of each pair being arranged side by side on shaft H4.

Each cam is are shaped, the camming surface being the arc of a circle with the center coinciding with the operating shaft. The cam is provided with a split hub I55, a screw I55 extending across a portion of the hub to clamp the cam to the shaft. The cams are positioned on the shaft so that the cams straddle the operating roller I52 for the switch which they operate.

In certain installations it is preferred to provide separate up and down switches for the direction circuits. Such arrangement has been illustrated in which switches I24 and I25 are direction circuit switches for controlling the stopping of the car, one. for up travel and the other for down. Each of these switches has only one operating cam. The leading edges of the cams for switches I20, I2I, I22 and I22 are substantially equally spaced from the rollers which they operate, so that a similar amount of rotative movement is required in one direction as in the other to open each switch. Similarly. the cams for operating switcha I24 and I25 are substantially equally spaced from the operating rollers of their switches. The cams are set so that their leading edges are increasingly farther from the rollers which their switches operate in the order of switches I20, I2I, I22, I22 and I24 or I25. In other words, upon rotative movement of the operating shaft in either direction, the switches are opened in the order of switches I20. I2I, I22, I22 and I24 or I25. The relative positions of the cams and the various switches with respect to the rollers with the shaft I4 in neutral position, that is, with the stopping lugs retracted. are indicated In Figure 2.

Assume that the elevator car is travelling in the up direction, causing the selector crosshead to be moved upwardly. Assume further that a call has been registered for the fourth floor. This call is picked up as the car arrives at a certain distance from the fourth floor, causing the deenergization of magnet II to extend the stopping lugs in the path of movement of the pawls. As continued movement of the crosshead takes place. the up pawl engages the fourth floor stopping lug, causing upward movement of sleeve 00. This causes clockwise rotative movement of shaft II4 as viewed in Figure 2, causing the opening of switches I20, I2I, I22, I22 and I25 in sequence as the car reaches'certain points in its approach to the fourth floor landing. The opening of these switches causes the car to slow down and stop at the fourth floor, the car being stopped as a result of the opening of switch I25 Just before the car reaches an exact level with the landing.

Upon restarting'the car, magnet 11 is energized to retract the stopping lugs. This releases the sleeve 55 which is returned to neutral position, causing the reclosing oi the operated switches. During downward movement of the car and crosshead, upon the picking up of a call, the lugs are extended into position as before for cooperation with the pawls and the down pawl engages the lug for the floor for which the call is picked up. This causes downward movement of the sleeve and counterclockwise rotative movement of shaft II4, causing the opening of switches I20, I2I, I22, I22 and I24 in sequence as the car reaches certain points in its approach to the landing. The opening of these switches causes the car to be slowed down and brought to a stop at the floor level, the stopping operation being eflected switch I24.

as a result of the opening of When the car is brought to a stop, the crosshead being driven by the car also comes to a stop with the sleeve moved to its operated position. If for any reason should the car and crosshead not come to a stop as a result of the opening of these switches, the pawl automatically disengages the stopping lug as sleeve 60 reaches its limit of travel to avoid any breakage of selector parts. This is effected by bevelling the corners of the stopping lugs and pawls as indicated at I60 and "SI in Figure 5. The angle of bevel is such that there is sufficient friction to effect movement of sleeve RU but upon sleeve 60 being stopped the pawl slides past the lug, spring 63 yielding to permit this movement.

In setting the stopping lugs 58 on sleeve 60,

the car is brought to an exact level with the floor for which a stopping lug is provided and, with the magnet 11 deenergized so that the sleeve 60 is in neutral position, the stopping lug is set so that its horizontal center is aligned with the horizontal center of elongated lug 59. Accurate setting is effected by means of a gauge which fits into slot I62 in lug 59, this gauge being provided with a slotted end to receive the end of the supporting arm 14 on the collar for the lug. In this way the stopping lug is located in correct position horizontally and it is also in the correct position radially for cooperation with the pawls 56 and 51.

Selectors of the construction shown in these drawingsmay be geared at different ratios. A ratio of 48 to 1, that is, forty-eight feet of car travel to one foot of crosshead movement, has been found satisfactory in average installations. The selector parts are illustrated for this ratio. The apertures in elongated lug 59 are illustrated as spaced a distance corresponding to one foot of car travel, that is, one-quarter of an inch apart. For installations without any short floor heights, the mounting brackets for the pawls are secured to the farthermost apertures 66 in elongated lug 59. This places the pawls in position to engage the stopping lug eight feet in advance of the floor for which the lug is provided.

A disc i63 marked off to provide a scale is secured to shaft H4 at one end thereof outside the bearing stand. This disc, in conjunction with pointer I64, is for setting the cams to operate the selector switches at the proper points. This scale is arranged symmetrically about a neutral point, that is, the point on the disc opposite the pointer I64 when sleeve 60 is in neutral position. Numerals may be applied to these marks as indicated. Each numbered mark on the scale represents one foot. Eight numbered marks have been provided on each side of the neutral point to correspond with the eight foot advance of the pawls.

As soon as the sleeve 60 is moved by a pawl,

the shaft H4 is moved correspondingly, as previously described. When the car has arrived at a point seven feet from the floor, the mark on the scale numbered 1 in the direction corresponding to the direction of car movement becomes opposite the pointer. Similarly, as the car arrives at each successive point one foot closer to the floor, the next numbered mark on the scale becomes opposite the pointer, until the car arrives at the floor level, when the mark numbered 8 becomes opposite the pointer. If the speed is such that an eight foot slow down is provided, the cams for operating switch I30 are set to open the switch as soon as rotative movement of shaft H4 takes place in either direction. If the speed is such that a less slow down distance is provided, these cams are set to such angular position on shaft H4 as to delay the opening of switch I30 until the slow down initiating point is reached. The cams for the other switches are set to open these switches at decreasing distances from the floor, the actual angular positions of these cams being dependent upon the total slow down distance and the characteristics of the particular installation. In any event, the cams for operating switches I31 and I35 are set to operate these switches just before the car arrives at exact floor level. The setting of the various cams is effected by moving shaft H6 by hand in each direction until the pointer is opposite a point which is a distance from the point marked 8 corresponding to the distance of the car from the floor at which it is desired. to have a particular switch open. The cam for that direction is then clamped onto shaft H4 in position to just crack open the switch.

In installations where a condition exists that the distance between a pair of adjacent floors is such that, with the stopping lugs set to correspond with this floor distance, the eight foot advance of the pawls would prevent the proper cooperation of the lugs for these floors with the pawls, the pawls are moved back toward center a sufficient distance to insure the proper cooperative relationship. This means a corresponding decrease in total slow down distance, so that the cams on shaft I M are set to compensate for this decrease. For example, if the pawls are set back to a six foot advance point, the cams for operating switches I 34 and I 35 are set to open these switches just before the mark 6 comes opposite the pointer, with the positions of the other cams set according to the slow down distance and characteristics of the particular installation.

At each of its ends the crosshead carries a frame I10 upon which are mounted a plurality of circuit controlling elements for cooperating with stationary circuit controlling elements mounted on floorbars I1I, one for each floor served by the car. These floor bars are spaced in accordance with the distance between the floors for which they are provided, and are mounted on round bars I12 secured to the bottom and top plates 2i and 22 of the floor controller. Details of this portion of the mechanism are shown in Figures 12, 13, 14, 15, 16, 1'1, 18 and 19.

Referring to these figures, each floor bar comprises an elongated flat bar I13 spanning mounting bars I12 and secured thereto by means of angle clamps I14 and screws I15, as shown in Figure 13. The bar is provided with a plurality of equallyspaced apertures 116 for mounting the various circuit controlling elements. In the arrangement shown in Figure 13, the fioor bar has mounted thereon a plurality of spring contacts and two operating cams. The spring contacts are mounted on the bar through the intermediary of insulating bases both on the front and back of the bar. These bases are arranged in duplicate sections I11, each section being formed with three slots H8 to receive the feet I of the guards WI for the contact springs. The slots are spaced in accordance with the distance between the apertures in bar I13 and in back of each slot is formed a circular porjection I 82 which extends partially into the aperture for locating the insulated section on the bar. The guard IBI for the spring contact is secured to the bar by a screw which extends throughan aperture formed centrally of the slot I18 for the base of the guard. 35

These screws also serve to clamp the front and rear insulated mounting sections together and as connecting screws for the leads to the spring contacts.

Contact springs I are secured to the spring guards by rivets which extend through clips I which cooperate with the flattened side of the head of the mounting screw to prevent the screw from turning. At the end of the contact spring is provided one or more silver contact tips I85. In the arrangement shown in Figure 13, eleven spring contacts are provided. The spring contact ill on the extreme right has two contact tips, the outer one of which is for engaging with a contacting cam carried by the crosshead frame and the inner one 01' which is for engaging with the contact tip of an oppositely arranged spring contact I81 when the outer contact tip is not engaged by the crosshead cams. A similar arrangement is provided for the spring contacts I" and I90 third and fourth from the right. The next five spring contacts IBI, I92, I92, I94 and IN to the left have single contact tips at their ends, the first two for cooperating with cams carried by the'crosshead frame and the next three for cooperation with contacts carried by the crosshead frame. The last two spring contacts I06 and Ill are arranged in the same manner as spring contacts Ill and I".

The crosshead frame I'll which carries the various elements for cooperating with the spring contacts above described is .provided with a mounting panel of insulating material arranged in duplicate sections 200. The frame is made up of angle members secured together in right angle relationship. The panel sections 2" are secured in abutting relation to the'sides of the cross angles as by screws 2". Each panel section is formed with a plurality of elongated slots 202 and with apertures 203 extending through the panel along the longitudinal center lines of the slots. The slots are located so as to be equally spaced throughout the width of the mounting panel, with the distance between their longitudinal center lines equal to the distance between the centers of the apertures I" in bar I13.

, The various cams and contacts for cooperating with the spring contacts on the floor bars are secured to brackets adjustably mounted in slots 202. The feet 2 and 2" of the brackets are of a width to fit within the slots 222 to properly locate the contacting elements and at the same time permit these elements to he slid longitudinally of the slots for purposes of adjustment. The brackets are secured to the panels by screws 2", which extend through apertures 20! into a nut 201 in back of the panel. As illustrated in Figures 16 and 18, thisnut is provided with an off-center threaded aperture to receive the screw and with an additional oil-center threaded aperture to receive an additional screw 2; The front end of screw 2" extends into aperture 202 to prevent the nut from turning and the outer end of the screw serves to receive binding posts for eflecting the connection of the contacting element in the system.

The contacting cam for engaging the outer contact tip of spring contact I9! is illustrated as arranged in four sections 2|||, 2H, 2|2 and 2|I. The upper three sections are of insulating material while the bottom section is of conducting material. Details of this portion of the mechanism are shown in Figures 16, 17 and 18. The brackets 2H and 2| I for the intermediate ones of these cam sections have their mounting arms 2|! and 2|! extending toward each other from their bases. The arm of bracket 2H for cam section 2|2 extends outwardly as shown in Figure 18 sumciently to mount cam section 2|2 outside of cam section 2| I, the arm being bulged to receive the extended portion of the arm 2| of cam 2 in telescopic relationship. This permits the two cam sections to be adjusted in overlapping positions. The outer two cam sections are maintained in abutting relationship with their adjacent inner sections.

When the outer contact tip of spring contact I91 is engaged by the cam, the inner contact tip is separated from the contact tip of spring contact I. This portion of mechanism is arranged in the direction control circuits but may be used for other purposes. When used for direction control in collective control systems, for example, there is provided a pair of spring contacts I96 and I91 per floor bar and the lowermost cam section 2|! is of a length to span the spring contacts I81 for those adjacent floors which are the farthest floor distance apart;

also, the insulated sections are set so that the upper insulated section 2|. engages the outer contact tip of spring contact Ill during upward movement of the crosshead slightly more than slow down distance in advance of the floor for which the spring contact is provided and insulated section 2|2 engages the outer contact tip of spring contact I91 during downward movement of the crosshead slightly more than slow down distance in advance of the floor for which the spring contact is provided. This is for the purpose of causing the car to pick up a down call when traveling up, provided no calls are registered for floors above, and to pick up an up call when travelling down, provided no calls are registered for floors below.

The contacts carried by the crosshead for cooperating with spring contacts III, III and I" are designated 220. Each of these contacts is of the same construction and is preferably of impregnated carbon, secured as by soldering to the arm 22| of its mounting bracket. The contact is tapered to provide a short duration of contact with the contact tip of the spring contact. These contacts and the spring contacts may be used for various purposes, such as picking up calls and resetting floor relays. When employed to pick up calls, they are set to engage spring contacts when the car is at a certain distance from the floor for which the spring contact is provided. The reset of the operated floor relay may be efl'ected at the same time. In certain instances, as where slow down is initiated at the time the call is picked up, this may be slow down distance in advance of the floor. It is preferred, however, to cause the slow down to be eiiected by the cooperation of the pawls with the stopping lugs. With such arrangement, each call pick up contact 22' is set to engage its spring contact to pick up the call at a distance in advance of the floor such that the stopping lug for that floor will be released at the proper time to be engaged by the pawl for the direction in which the car is travelling.

Contacts in addition to the call pick up contacts may be provided for cooperating with the spring contacts, these additional contacts being set to be in engagement with the tips of the spring contacts for a floor when the car is level with the floor. This arrangement may be used for resetting floor relays operated after the call for that floor has been picked up. These additional. contacts may be used for other purposes, such as, for example, in the circuits for causing automatic door opening operation in response to the pushing of a hall button at the floor at which the car is positioned.

When contacts 220 are used for call pick up and floor relay reset and also for resetting floor relays operated after the slow down has been initiated, in an installation having one push button per floor in the elevator car and up and down hall buttons at intermediate floors, one column of three contacts is provided for the car button circuits, as shown in the column 2I9 of contacts for cooperating with spring contacts I95, another column oftwo contacts is provided for the up hall buttons, as shown in column 228 of contacts for cooperating with spring contacts I94, and a third column of two contacts is provided for the down hall button circuits, as shown in column 229 of contacts for cooperating with spring contacts I93.

The contacting cam for cooperating with spring contact I92 is arranged in four sections 222, 223, 224, 225. The two upper sections 222 and 223 are arranged for telescopic adjustment; similarly, the two lower sections 224 and 225 are arranged for telescopic adjustment, such mounting having been described in connection with cam sec tions 2 and 2I2. All of these cam sections are of conducting material. This arrangement also may be used for various purposes, including certain operations in the control of elevator cars in which the starting of the cars is under the control of a car attendant and the stopping is controlled in response to push buttons for the various floors. In such control arrangement, one spring contact I92 is provided on each floor bar for the floors served by the car.

The cam for operating spring contact I9I is arranged in two sections, designated 226 and 221. As in the case of the cam sections 2H and 2I2, sections 226 and 221 are arranged in telescopic relationship for adjustment purposes. Both sections of the cam are conducting. Such arrangement may be used for various purposes in elevator systems, such as the control of hall lanterns and car position indicators. When used for the control of the position indicators, one spring contact I9I is provided per floor for the floors served by the car. When used for control of hall lanterns,

two columns of spring contacts of one contact per floor served by the car, with a separate contacting cam for each column, are provided, one column for up hall lanterns and the other for down hall lanterns, or there may be one contact per floor bar for floors below the uppermost floor served by the car for the up hall lanterns in the one column and one spring contact per floor bar for floors served by the car above the lowermost floor served by the car in the other column.

- The contacting cam for engaging the outer contact tip of spring contact I90 is arranged in two sections 238 and 23I. .The lower section 238 is of conducting material and the upper section 23! of insulating material. These cam sections are mounted for telescopic adjustment. The contacting cam for engaging the outer contact tip of spring contact I86 is of a similar construction, being arranged in two sections, the upper one 232 of which is the conducting section and the lower one 233 the insulated section. These contacting cams and spring contacts I86, I81, H83 and H also may be used for various purposes in elevator circuits. For example, when used for scheduling, spring contacts I88 and I99 are arranged on the floor bar for the upper scheduling floor and spring contacts I86 and I81 are arranged on the fioor bar for the lower scheduling floor. The conducting sections of the cams are positioned so that they are in engagement with the contact tips of their respective cooperating spring contacts when the car is at the scheduling floor for which the spring contact is provided. With such arrangement, when the lower cam section 239 engages the outer tip of spring contact I96 as the car approaches the lower scheduling floor, the inner contact tip is disengaged from the tip of spring contact I88. The spring contacts remain in this condition with the car stopped at the scheduling floor. However, should the car run to a floor below the scheduling floor, upon its return thereto the upper insulated section 23I causes the separation of spring contacts I and I88 before contact is made between the outer contact tip of spring contact I90 and conducting section 236, thus giving the desired control of the circuits under such conditions. The operation is similar for the cam sections 232 and 233 and spring contacts I81 and H86 in that, in returning to the upper scheduling floor from the floor above, the lower insulated section 233 separates spring contacts 181 and I86 before the outer contacttip of spring contact I86 contacts the conducting section 232 of the cam.

The arrangement of the spring contacts so that the springs extend inwardly from the floor bars perpendicular to the plane of the crosshead panel sections, with the flats of the springs vertical, takes up a minimum of space, permitting the floor bars to be placed close together. With this arrangement the contact springs are deflected horizontally by the vertical movement of the crosshead. Also, the spring contacts and their cooperating contacting elements on the crosshead insure positive circuit connections as there are no joints or lost motion connections involved.

The left hand panel as viewed in Figure 12 carries two switches 231 and 238 of the same construction as the switches on top of the selector, previously described. These switches are shown in Figures 14 and 15. The frame I40 of each switch is secured to an extension bracket 240 in turn welded to an elongated strap 24 I This strap extends into the slot 202 in the panel and is secured to the panel as by screws 206 extending through aperture 203 into nut 201 in back of the panel, as previously described.

Each switch is provided with an operating cam 242, one for each floor. Each cam has a threaded shank 243. This shank extends through the floor bar aperture I16 opposite the switch. The shank is clamped to the floor bar by means of an adapter 244 on the cam side of the bar and a nut 245 on the other side. The adapter is provided with prongs 241 fitting over the floor bar. This enables the cam to be adjusted by loosening the nut 245 and turning the shank with a screw driver and to be clamped in adjusted position by taking up on the nut.

This arrangement may he used for various purposes in elevator circuits. For example, the switches may be used to control the automatic opening or" the hatchway doors and car gate. By connecting the contacts of these switches in parallel relationship, they may be utilized to provide a door zone limit, that is, a zone in which the car must be in making a stop in order for the door opening operation to be initiated. With the switch contacts connected in parallel relationship, the circuit controlled thereby is not broken by them unless both of them are open. By setting these switches so that the midpoints of their rollers are on the centers of the operating cams with the car stopped at a floor, a maximum door zone limit is obtained.- This distance may be decreased by spreading the switches apart as indicated in Figure 12. A similar arrangement may be had by providing switches with making contacts and connecting these contacts in series relationship. These switches may be used for other purposes, as to control the stopping of the car in certain installations where the pawls and Stopp ng lugs are omitted. V

The frame I10 is provided with threaded apertllres 241 on each end thereof which are utilized to mount gauges for setting the floor bars. With the gauges in place, the car is brought to an exact floor level and the floor bar for that floor is then moved to and clamped in position opposite the g u es.

The contacting elements which are provided on the floor bars and on the panels of the crosshead frames are determined by the particular installations. In certain relatively simple installations, a few contacting elements are provided on each floor bar and on the crosshead panels. In such event, insulated mounting bases are provided only for the contacting elements used on the floor bars. Similarly, crosshead panels are provided only for the contacting elements provided on the crosshead panel. In some installations, on the other hand, a large number of contacting elements are used both on the crosshead and, if the number of them is suincient, floor bars are provided on both sides of the selector for mounting the stationary elements, and panels are provided on both crosshead frames for the moving elements. The positions of the contacting elements may vary depending upon the particular installation. The use of insulated bases and panels in sections enables these diflerent combinations to be eifected without any change in design of apparatus. In a system such as disclosed in the patent to Lewis, Waters and Krauer, No. 2,101,146, granted December 7, 1937, previously referred to, the contacting cam, made up of sections 2M, III, II! and Ill, and the columns M9, 228 and 229 of contacts are provided on the crosshead and spring contacts I81, I96, I95, I94 and I" are provided on the door bars. In other types of systems. other combinations are used. It is to be understood that the "mechanism with suitable combinations of apparatus is applicable not only to systems in which push buttons control the operation of the car but also to those in which push buttons are not provided or those in which push buttons are utilized to control the operation of signalling mechanism.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

Control mechanism for an elevator car serving a plurality of landings comprising; switching mechanism; rotatable means; a plurality of lugs, one for each of said landings, mounted on said rotatable means in spaced relation in accordance with the distance between the landings for which the lugs are provided; movable means actuated in accordance with car movement; a member carried by said movable means for cooperation with the landings for which they said lugs; electromagnetically controlled means for eiiecting rotatlve movement of said rotatable means to move said lugs into and out of the path of movement of said member, said member upon extension of said lugs into its path of movement acting to engage the next lug; and means operable by the coaction of said member with said lug as movement of said movable means continues for actuating said switching mechanism.

2. Control mechanism for an elevator car serving a plurality of landings comprising; a movable member; a plurality of lugs, one for each of said landings; means for securing said lugs on said movable member in spaced relation in accordance with the distance between the landings for which they are provided; a pair of oppositely disposed pawls for engaging said lugs; means for moving said pawls in accordance with car movement; means for operating said movable member to move said lugs into and out of the path of movement of said pawls, one or the other of saidpawls, depending upon the direction in which they are moving, acting upon extension of said lugs into the path of movement of said pawls to engage the next lug in the direction therefrom in which the pawls are moving and thereby to move said movable member in said direction as movement of said pawl continues; switching mechanism; and means operable by movement of said movable member by a pawl for actuating said switching mechanism.

3. Control mechanism for an elevator car serving a plurality of landings comprising; a movable member actuated in accordance with movement of the elevator car; an elongated member adapted for movement along a path parallel to that of said movable member; a plurality of lugs. one for each of said landings; means for securing said lugs on said elongated member in spaced relation in accordance with the distance between are provided; a pair of oppositely disposed pawls, one for each direction of movement of said movable member, mounted on said movable member for engaging said lugs; means for operating said elongated member to move said lugs into and out of the path of movement of said pawls, said pawl for the direction in which said movable member is,

being actuated acting upon extension of said lugs into the path of movement of said pawls to engage the next lug in said direction therefrom and thereby to move said elongated member from a neutral position in said direction as movement of said movable member continues; means operable upon retraction of said lugs after movement of said elongated member by a pawl to return said elongated member to its neutral position; switching mechanism; and means operable by movement of said elongated member by a pawl for actuating said switching mechanism.

4. A selector for an elevator car serving a plurality of landings comprising; an elongated guide; a member slidably mounted on said guide a plurality of lugs, one for each of said landings means for securing said lugs on said member in spaced relation in accordance with the distance between the landings for which they are provided; a crosshead actuated in accordance with movement of the elevator car; a pair of oppositely disposed pawls, one for each direction of movement of said crosshead, mounted on said crosshead for engaging said lugs, said member being biased to extend said lugs into the path of movement of said pawls; electromagnetic means for operating said member to re- 16 tract said lugs into position to be clear of said pawls during movement of said crosshead, said pawl for the direction in which said crosshead is being actuated acting upon extension of said lugs to engage the next lug in said direction therefrom and thereby to move said member from a neutral position longitudinally on said guide in said direction as movement of said crosshead continues; means operable upon retraction of said lugs after movement of said member on said guide by a pawl to return said member to its neutral position; switching mechanism; and means operable by movement of said member on said guide for actuating said switching mechanism.

5. A selector for an elevator car serving a plu rality of landings comprising; an elongated guide; a pair of wheels, one at each end of said guide; a sleeve slidably mounted on said guide; means forming a closed loop comprising said sleeve and flexible means connected to opposite 'movement of the elevator car; a pair of oppositely disposed pawls mounted on said crosshead for engaging said lugs, said sleeve being biased to an angular position to extend said lugs into the path of movement of said pawls; an electromagnet; means operable by said electromagnet for turning said sleeve in a direction to retract said lugs into position to be clear of said pawls during movement of said crosshead, said pawl for the direction in which saidcrosshead is being actuated acting upon extension of said lugs to engage the next lug in said direction therefrom and thereby to move said sleeve from a neutral position longitudinally on said guide in said direction as movement of said crosshead continues; means operable upon retraction of said lugs after movement of said sleeve on said guide by a pawl to return said sleeve to its neutral position; and switching mechanism operable by rotative movement of one of said wheels by said flexible means upon longitudinal movement said sleeve on said guide. 6. A selector for an elevator car serving a plurality of landings comprising; an elongated vertical guide; a pair of Wheels. one at each end of said guide; a tubular member slidably mounted on said guide; means forming a closed loop comprising said tubular member and flexible means connected to opposite ends of said tubular member and extending oppositely therefrom to and around said wheels; a plurality of lugs, one for each of said landings; means for securing said lugs on said tubular member in spaced relation in accordance with the distance between the landings for which they are provided; a vertically movable crosshead; means for actuating said crosshead in accordance with movement of the elevator car; a pair of oppositely disposed pawls mounted on said crosshead for engaging said lugs, said tubular member being biased to an angular position to extend said lugs into the path of movement of said pawls; an electromagnet; means operable by said electromagnet for turning said tubular member in a direction to retract said lugs into position to be clear of said pawls during movement of said crosshead, said pawl for the direction in which said crosshead is being actuated acting upon extension of said lugs to engage the next lug in said direction therefrom and thereby to move said tubular member from a neutral position longitudinally on said guide in said direction as movement of said crosshead continues; means for overbalancing said tubular member; means for supporting said overbalancing means in position to support said tubular member in neutral position, said overbalancing means acting upon retraction of said lugs after movement of said tubular member on said guide in one direction to return said tubular member to its neutral position and said tubular member acting upon retraction of said lugs after movement thereof on said guide in the opposite direction to return to its neutral position under the influence of gravity; and switching mechanism operable by rotative movement of one of said wheels by said flexible means upon longitudinal movement of said tubular member on said guide.

7. A selector for an elevator car serving a plurality of landings comprising; an elongated vertical guide; a sprocket wheel at one end of said guide; an idler wheel at the other end of said guide; a sleeve slidably mounted on said guide; a sprocket chain connected at one end to the end of said sleeve toward said sprocket wheel and extending therefrom to and around said sprocket Wheel; a second chain connected at one end to the 'other end of said sleeve and extending oppositely therefrom to and around said idler wheel; a rod connecting the other ends of said chains together to form a closed loop; a plurality of arms, one for each of said landings, secured on said sleeve and spaced thereon in accordance with the distance between the respective landings; a stopping lug on the end of each arm; a vertically movable crosshead; means for actuating said crosshead in accordance with movement of the elevator car; a pair of oppositely disposed pawls mounted on said crosshead for engaging said lugs; an electromagnet; means operable by said electromagnet for turning said sleeve in a direction to retract said lugs into position to be clear of said pawls during movement of said crosshead; means biasing said sleeve for turning in a direction to extend said lugs into the path of movement of said pawls, said pawl for the direction in which said crosshead is being actuated acting upon extension of said lugs to engage the next lug in said direction therefrom and thereby to move said sleeve longitudinally on said guide from a neutral position in said direc tion as movement of said crosshead continues; a weighted member slidably arranged on said rod for overbalancing said sleeve; means supporting said weighted member in position to support said sleeve in neutral position; means secured to said rod for lifting said weighted member upon movement of said sleeve longitudinally on its guide in one direction, said weighted member acting upon retraction of said lugs to return said sleeve to its neutral position and said supporting means by supporting said weighted member upon longitudinal movement of said sleeve on its guide in the opposite direction from neutral, discontinuing said overbalance, said sleeve acting under such conditions upon retraction of said lugs to return to its neutral position under the influence of gravity; and switching mechanism operable by rotative movement of said sprocket wheel by said sprocket chain upon longitudinal movement of said sleeveon said guide.

8. Control mechanism for an elevator car serving a plurality of landings; switching mechanism; an elongated guide; movable means slidably mounted on said guide; a pair of wheels, one at each end of said guide; flexible means connected to the ends of said movable means and extending around said wheels to form a closed loop'; means operated in accordance with car movement for moving said movable means longitudinally on said guide from a neutral position; a weighted member slidably arranged on said flexible means for overbalancing said movable means; means supporting said weighted member for supporting said movable means in neutral position; and means secured to said flexible means for lifting said weighted member upon movement of said movable means in one direction, said weighted member acting under such conditions to return said movable means to its neutral position, and said supporting means supporting said weighted member upon movement of said movable means in the opposite direction to discontinue said overbalance, said movable means acting under such conditions to return to its neutral position under the influence of gravity.

9. Selector mechanism for an elevator car serving a plurality of landings comprising; a frame; a movable member; means for guiding the movement of said member in said frame; a sprocket wheel rotatably mounted on said member; a stationary sprocket chain secured to said frame parallel with the path of movement of said member and meshing with said sprocket wheel; and means for rotating said sprocket wheel in accordance with movement of the elevator car, whereby said member is moved in accordance with movement of the car but at one-half the peripheral speed of said sprocket wheel.

10. Selector mechanism for an elevator car serving a plurality of landings comprising; an endless sprocket chain; a frame; a pair of wheels mounted on said frame around which said chain passes; means acting through one of said wheels to drive said sprocket chain in accordance with movement of the elevator car; a stationary sprocket chain secured to said frame parallel with one run of said endless chain; a movable member; and a sprocket wheel rotatably mounted on said member and meshing on one side with said stationary chain and on the other with said one run of said endless chain, whereby upon rotative movement of said sprocket wheel by said endless chain said member is moved in accordance with movement of the car but at one-half the speed of said endless chain.

11. Selector mechanism for an elevator car serving a plurality of landings comprising; an elongated frame; a pair of wheels, one at each end of said frame; an endless sprocket chain passing around said wheels; means acting through one of said wheels to drive said sprocket chain in accordance with movement of the elevator car; a crosshead; means for guiding said crosshead for movement toward either end of said frame; a sprocket wheel rotatably mounted on said crosshead and meshing with one run of said chain; and a stationary sprocket chain meshing with said sprocket wheel on the side opposite to said endless chain, whereby upon rotative movement of said sprocket wheel by said endless chain said crosshead is moved in accordance with movement of the car but at one-half the speed of said endless chain.

12. Selector mechanism for an elevator car serving a plurality oi landings comprising; a frame having two end plates; a sprocket wheel mounted on one of said end plates; an idler wheel mounted on the other end plate; an endless sprocket chain passing around said wheels; means acting through said sprocket wheel to drive said sprocket chain in accordance with movement of the elevator car; a crosshead; means for guiding said crosshead for movement toward either end plate; an additional sprocket wheel rotatably mounted on said crosshead and meshing with one run of said chain; and a stationary sprocket chain meshing with said additional sprocket wheel on the side opposite to said endless chain, rotative movement of said additional sprocket wheel by said endless chain causing said additional sprocket wheel to travel on said stationary chain and thus cause movement of said crosshead in accordance with movement of the car but at onehalf the speed of said endless chain.

EDWARD LEE DUNN. 

